<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style type="text/css">
        body{
            margin: 0px;
            padding: 0px;
        }
        .wrapper{
            width: 100%;
            height: 500px;

        }
        .head{
            width: 1226px;
            height: 100px;
            margin: 0 auto;

        }
        .phone{
            width: 84px;
            height: 88px;
            font-size: 16px;
            position: absolute;
            margin-top: 30px;
            margin-left: 40px;

        }
       .phone:hover{
            color: darkorange;
            cursor: pointer;
        }
        .miss{
            width: 100%;
            height:0px;
            margin-top:100px;
            background-image: url("phone.png");
            position: absolute;
        }

        .phone:hover+.miss{
            height: 200px;
            transition-property: height;
            transition-duration: 0.3s;
        }

    </style>
</head>
    <body>
        <div class="wrapper">
            <div class="head">
                <div class="phone">小米手机</div>
                <div class="miss"></div>
            </div>
               <!-- <div class="miss"></div>-->
        </div>
    </body>
</html>